import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.Socket;
import java.util.Scanner;

public class TcpEchoClient {
    private Socket socket=null;

    public TcpEchoClient(String serverIp,int port) throws IOException {
        //这个操作相当于让客户端和服务器建立tcp连接
        //这里的连接连上了，服务器的accept就会返回
        socket=new Socket(serverIp,port);
    }

    public void start(){
        Scanner sc=new Scanner(System.in);
        try (InputStream inputStream=socket.getInputStream();
             OutputStream outputStream=socket.getOutputStream()){
            PrintWriter printWriter=new PrintWriter(outputStream);
            Scanner scannerFromSocket=new Scanner(inputStream);
            while (true){
                //1.从键盘上读取用户输入
                System.out.print("->");
                String request=sc.next();
                //2.把读取的内容构造成请求发送给服务器，此处的发送是带有换行的
                printWriter.println(request);
                printWriter.flush();
                //3.从服务器读取响应内容
                String response=scannerFromSocket.next();
                //4.把响应结果显示到控制台上
                System.out.printf("req: %s; resp: %s\n",request,response);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) throws IOException {
        TcpEchoClient client=new TcpEchoClient("127.0.0.1",9090);
        client.start();
    }
}
